In recent years it has become popular to package various types of material, especially medicinal or quasi-medicinal types in sealed cartridges, insertable in a suitable type of holder and/or ejector device, for purposes of preserving purity of the medicament and the like, insuring a patient of accurately measured quantities, as well as minimizing effort now required in introducing bulk amounts of material into a syringe and ejecting measured quantities thereof, for example. Various previous efforts in this direction are illustrated and described in various prior U.S. patents, particularly U.S. Pat. No. 3,581,399 to Dragan, dated June 1, 1971, in which a typical example of loaded cartridge is illustrated in conjunction with one type of holder and discharge device.
Other efforts have been made to produce similar devices, one of these comprising the subject matter of prior U.S. Pat. No. 3,900,954, also to Dragan, dated Aug. 26, 1975, and comprising a simpler version than in Dragan's patent, U.S. Pat. No. 3,581,399.
It has been found in the operation of the Dragan devices, particularly relative to the curved discharge end of the capsule or cartridges that there have been occasions when the leading end of the ejecting plunger or the piston within the cartridge pushed through the wall adjacent the outer end of the cartridge. Particularly for purposes of obviating this difficulty and also for providing an improved cartridge not subject to the difficulties of Dragan's cartridges and which is free of such difficulties, the present invention has been devised and details thereof are set forth hereinbelow.
Further, certain additional constructions in cartridges of the type described above are disclosed in prior U.S. Pat. No. 2,505,028 to Boeger, Dated Apr. 25, 1950.